Search results for "DFI"
showing 10 items of 128 documents
Biological nitrogen removal from municipal landfill leachate: low-cost nitrification in biofilters and laboratory scale in-situ denitrification.
2002
The slow leaching of nitrogen from solid waste in landfills, resulting in high concentrations of ammonia in the landfill leachate, may last for several decades. The removal of nitrogen from leachate is desirable as nitrogen can trigger eutrophication in lakes and rivers. In the present study, a low-cost nitrification-denitrification process was developed to reduce nitrogen load especially in leachates from small landfills. Nitrification was studied in laboratory and on-site pilot aerobic biofilters with waste materials as filter media (crushed brick in upflow filters and bulking agent of compost in a downflow filter) while denitrification was studied in a laboratory anoxic/anaerobic column …
Methane oxidation in a boreal climate in an experimental landfill cover composed from mechanically–biologically treated waste
2007
The present study evaluated microbial methane (CH4) oxidation in a boreally located outdoor landfill lysimeter (volume 112 m3, height 3.9 m) filled with mechanically-biologically treated waste (MBT residual) and containing a cover layer made from the same MBT residual. The calculations based on gas emission and pore gas measurements showed that, between April and October 2005, a significant proportion (96%) of the methane produced (23 l CH4 m(-2) d(-1)) in the lysimeter was oxidized. Methane was oxidized mainly at the depths of 35-75 cm, as indicated by the upward decrease both in the methane concentration and in the methane-to-carbon dioxide ratio in the pore gas. Lower methane oxidation (…
Evaluation of the current status of operating and closed landfills in Russia, Finland and Ireland with regard to water pollution and methane emission
2003
The annual production of municipal solid wastes (MSW) in Russia, Finland and Ireland in the late 1990s accounts for 37.5, 2.5 and 2.05 mln. tonnes or 252, 488 and 566 kg per capita, respectively. 96.5, 64 and 91% of these wastes (for Russia, Finland and Ireland, correspondingly) are currently disposed of via landfilling. However, nowadays, MSW management in these countries is undergoing drastic changes (source separation, closure of old landfills, reduction of the number of landfills etc.) forced by recent legislation set by the European Union and Russian authorities. This paper evaluates the current status of MSW landfills, as well as information on current leachate and methane emissions i…
Soil biogeochemistry and microbial community dynamics in Pinus pinaster Ait. forests subjected to increased fire frequency.
2022
Fire frequency might increase in many fire-dominated ecosystems of the world due to the combined effects of global warming, land-use change and increased human pressures. Understanding how changes in fire frequency can affect the main soil biogeochemical dynamics, as well as the microbial community, in the long term is utmost important. Here we determined the effect of changes in fire frequency and other fire history characteristics on soil C and N dynamics and the main microbial groups (using soil fatty acid profiles), in Pinus pinaster forests from central Spain. Stands were chosen to differ in the number of fires (1 to 3) occurred between 1976 and 2018, in the time elapsed since the last…
Internal leachate quality in a municipal solid waste landfill: Vertical, horizontal and temporal variation and impacts of leachate recirculation
2008
The aim of this study was to monitor and characterise internal leachate quality at a Finnish municipal solid waste landfill (Lahti, Kujala, in operation for approximately 50 years) to provide information about its horizontal and vertical variation as well as effects of leachate recirculation on leachate quality. The study area (approximately 4h) of the landfill had 14 monitoring wells for leachate quality monitoring over a 2-year period. The leachate was monitored for COD, BOD, TKN, NH4-N, Cl, pH and electric conductivity. The results showed high horizontal and vertical variability in leachate quality between monitoring wells, indicating that age and properties of waste, local conditions (e…
Greening MSW management systems by saving footprint: The contribution of the waste transportation.
2018
Abstract Municipal solid waste (MSW) management constitutes a highly challenging issue to cope with in order of moving towards more sustainable urban policies. Despite new Standards call for recycling and reusing materials contained in the urban waste, several municipalities still use landfilling as a waste disposal method. Other than the environmental pressure exerted by these plants, waste transportation from the collection points to the landfill needs a specific attention to correctly assess the whole burden of the waste management systems. In this paper, the Ecological Footprint (EF) indicator is applied to the actual MSW of the city of Palermo (Sicily). Results show that the effects pr…
Previous fire occurrence, but not fire recurrence, modulates the effect of charcoal and ash on soil C and N dynamics in Pinus pinaster Aiton forests.
2021
Abstract Understanding the effects of fire history on soil processes is key to characterise their resistance and resilience under future fire events. Wildfires produce pyrogenic carbonaceous material (PCM) that is incorporated into the soil, playing a critical role in the global carbon (C) cycle, but its interactions with soil processes are poorly understood. We evaluated if the previous occurrence of wildfires modulates the dynamic of soil C and nitrogen (N) and microbial community by soil ester linked fatty acids, after a new simulated low-medium intensity fire. Soils with a different fire history (none, one, two or three fires) were heat-shocked and amended with charcoal and/or ash deriv…
Hunting for valuables from landfills and assessing their market opportunities A case study with Kudjape landfill in Estonia
2017
Landfill mining is an alternative technology that merges the ideas of material recycling and sustainable waste management. This paper reports a case study to estimate the value of landfilled materials and their respective market opportunities, based on a full-scale landfill mining project in Estonia. During the project, a dump site (Kudjape, Estonia) was excavated with the main objectives of extracting soil-like final cover material with the function of methane degradation. In total, about 57,777 m3 of waste was processed, particularly the uppermost 10-year layer of waste. Manual sorting was performed in four test pits to determine the detailed composition of wastes. 11,610 kg of waste was…
Weathering of evaporites: natural versus anthropogenic signature on the composition of river waters
2015
Weathering of evaporites strongly influences the chemistry of continental runoff, making surface waters poorly exploitable for civil uses. In south-central Sicily, this phenomenon is worsened by the occurrence of abandoned landfills of old sulphur and salt mines. The industrial evolution of the Bosco-S. Cataldo mining site leaved two landfills from the early exploitation of a sulphur mine followed by that of a kainite deposit. In particular, the weathering of these landfills leads the dissolved salt (TDS) values up to about 200 g l−1 in the Stincone–Salito Stream waters. This process induces the V, Cr and Fe desorption from sediments and particulates in the aqueous phase under reducing cond…
Probabilistic risk assessment of the exposure to polybrominated diphenyl ethers via fish and seafood consumption in the Region of Valencia (Spain)
2013
The study was carried out to estimate the dietary intake of polybrominated diphenyl ethers (PBDEs) in the Region of Valencia (Spain) in order to evaluate the resultant risk. The PBDE levels in fish and seafood (a total of 206 samples) were determined. Dietary intake was estimated using results of PBDE analyses in fish and seafood marketed in the Region of Valencia over the period 2007-2012 and data of the first Valencian Food Consumption Survey, conducted in 2010. Two scenarios were assumed for left-censored results: the lower-bound (LB) scenario, in which unquantified results (below the limit of quantification (LOQ)) were set to zero and the upper-bound (UB) scenario, in which unquantified…